This invention relates to a process for preparing organic sulfone compounds. More particularly, this invention relates to an improved process for oxidising organic sulfide compounds in a relatively simple and efficient manner to the corresponding organic sulfone compound.
Organic sulfone compounds, as well as oxidation processes for their preparation, are well known in the art. Heretofore, organic sulfone compounds generally have been prepared by one of two oxidation processes which employ a peracid as the oxidising agent. One process, the so called "generator process", involves separately generating an anhydrous peracid oxidizing agent on site to be used for the oxidation of the organic sulfide compound at some later time. The other process, the so called "in-situ" process is a one-step process which calls for the generation of the peracid oxidising agent in-situ in the presence of the organic sulfide compound sought to be oxidized. Although they are relatively simple and efficient, both known processes suffer from a number of inherent disadvantages. For example, it is generally recognized that both of the previously disclosed peracid oxidation processes usually give rise to organic sulfone compounds that are contaminated with an acceptably large amount of the corresponding sulfoxide compound as a by-product. This makes it necessary to carry out elaborate and cumbersome purification procedures which result in relatively low yields of the sulfone product. In addition, the generator process suffers from a further disadvantage in that it requires the generation and handling of the unstable and potentially hazardous anhydrous peracid. The conventional "in-situ" process, although simple and safe to operate, generally requires expensive high boiling reaction solvents, extended reaction periods, and high reaction temperatures with the concomitant increased probability of thermal degradation of reaction products. Consequently, there exists a need for a more effective process for converting organic sulfide compounds in organic sulfone compounds with enhanced sulfone yields coupled with lower reaction temperatures and shorter reaction periods.